Search

Copyright of Cryptogamie Mycologie is the property of Museum National d'Histoire Naturelle, Paris and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Sickle cell retinopathy is the main ophthalmologic complication of sickle cell syndrome. Optical coherence tomography (OCT) and optical coherence tomography-angiography (OCT-A) permit demonstration of central retinal involvement. The goal of this study is to determine whether central retinal involvement is predictive of peripheral retinal ischemia., Materials and Methods: We carried out a retrospective study of 31 patients with sickle cell disease who underwent a complete ophthalmologic examination. We focused on capillary density of the superficial and deep plexuses and the central avascular surface by OCT-A, and retinal layer thickness by OCT. All of the findings obtained by OCT-A and OCT were classified according to the Goldberg stages on fluorescein angiography., Results: A thinning of the mean and temporal deep plexus capillary layer as well as a loss of the temporal density of the superficial plexus capillaries are significantly higher in the case of proliferative sickle cell retinopathy (P=<0.05). A significant negative correlation is observed between the mean and temporal density of the superficial (R=-0.31; P=0.02 and R=-0.43; P=0.0009) and deep plexus capillaries (R=-0.39; P=0.003 et R=-0.43; P=0.0009) and the Goldberg stage in fluorescein angiography., Conclusion: The study of the temporal capillary densities of the superficial and deep plexuses on OCT angiography may prove to be a useful tool for the ophthalmologist in order to diagnose patients at risk for proliferative sickle cell retinopathy., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Dry eye disease is a multifactorial disease affecting the lacrimal functional unit and which has a significant impact on the quality of life of patients. This pathology works as a vicious circle at the ocular surface in which hyperosmolarity of the tear film plays a key role. This review intends to describe the different reported intracellular effects induced by hyperosmolarity in cells: alteration of cytoskeleton, cell cycle slowdown, adaptation mechanisms triggered as restoration of cell volume and accumulation of compatible osmolytes, the crucial role of the osmoprotectant factor Nuclear Factor of the Activated T cells-5 (NFAT5), apoptosis, as well as oxidative stress and inflammatory responses caused by this particular condition. Reported effects of hyperosmolarity in the experimental studies specific of dry eye disease concerning ocular surface cells will be described in parallel. Indeed, these data allow to understand a part of the pathophysiology of the disease, and specially the links between tear hyperosmolarity and inflammation of the ocular surface, the second key of the pathology phenomenon., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Unlabelled: Thrombocytopenia is a current situation for making a blood smear in routine practice in a medical analysis laboratory. Recent automated hematology analyzers enumerate platelets and generate histograms and specific flags. Operators must be aware of the characteristics of their analyzer in order to avoid spurious results in the case where microscopy review is not possible., Objective: We evaluated the diagnostic performance of various graphical anomalies in the detection of large platelets and platelet clumps., Patients and Methods: Three hundred cases of thrombocytopenia were included in the study on the basis of a platelet count less than 150 × 10(9)/L. This evaluation is expressed by the results of the sensitivity, specificity, positive predictive value and negative predictive value compared to the microscopic review of blood smear., Results: Graphical performances are variable according to microscopic review of blood smears. Indeed, a not fitted curve is the most sensitive change on platelet histogram to the presence of large platelet. A high specificity to the presence of platelet clumps is announced when the platelet curve fails to return to the baseline. Moreover, characteristic findings on the DIFF scattergram are very specific to the presence of platelet clumps., Conclusion: A normal platelet histogram can validate with great confidence thrombocytopenia in cases where a blood smear cannot be read immediately., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

The most common form of diabetes, type 2 diabetes (T2D) is a major Public Health issue which is receiving a great deal of attention both in industrial and public research, in order to develop new and more effective drugs. The hyperglycaemia of T2D is the result of two interdependent defects : decreased biological efficacy of insulin in target tissues (insulin resistance), and a decreased capacity for beta cells to secrete insulin in response to glucose. Furthermore, hyperglycaemia evolves with time and even with rigorous treatment there is a progressive deterioration of glucose homeostasis. Seventy five percent of DT2 patients are obese and show a perturbed lipid profile. beta-cell plasticity is a unique property of these cells to adapt their number and volume (beta-cell mass) and their function to the increased secretory demand linked to insulin resistance. This is well documented in physiological (pregnancy) as well in pathophysiological conditions (obesity, acromegaly). Although the lack of reliable techniques makes it very difficult to document it in humans, this property is likely altered in DT2, mainly as a consequence of the prolonged exposure of islet cells to high plasma levels of glucose and free fatty acids (gluco-lipotoxicity). The mechanisms by which hyperglycaemia and hyperlipidemia exert their deleterious effects on the beta-cell include the generation of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) and Advanced Glycosylation End Products (AGE). Altogether the prevailing clinical and experimental data urge us to consider that the pathophysiology of DT2 lies, at least in part, the inability of beta-cells to adapt their functional mass to the prevailing insulin demand. This re-evaluation of the pathophysiology of DT2 stimulates the research of new therapeutic approaches aimed at maintaining and/or restoring the functional beta-cell mass by targeting the mechanisms responsible for its decrease.

Flagella and cilia are elaborate cytoskeletal structures conserved from protists to mammals, where they fulfil functions related to motility or sensitivity. We demonstrate a novel role for the flagellum in the control of cell morphogenesis and division of Trypanosoma brucei. To investigate flagellum functions, its formation was perturbed by inducible RNA interference silencing of components required for intraflagellar transport (IFT), a dynamic process necessary for flagellum assembly. First, we show that down-regulation of IFT leads to assembly of a shorter flagellum. Strikingly, cells with a shorter flagellum are smaller, with a direct correlation between flagellum length and cell size. Detailed morphogenetic analysis reveals that the tip of the new flagellum defines the point where cytokinesis is initiated. Furthermore, when new flagellum formation is completely blocked, non-flagellated cells are very short, lose their normal shape and polarity and fail to undergo cytokinesis. We show that flagellum elongation controls formation of cytoskeletal structures present in the cell body that act as molecular organisers of the cell.

Objectives: This prospective study aimed to evaluate the impact of oocyte dysmorphy on the fertilization rate and embryonic development rate in an ICSI programme., Patients and Methods: Three hundred and two couples have been included during 302 ICSI cycles, and 1970 oocytes have been studied in 4 ART centres. After decoronisation, 18 morphological criteria, including the size and shape of the oocyte, the thickness of the zona pellucida, the presence or not of debris in the perivitelline space, as well as the appearance of the cytoplasm and polar body have been noted., Results: In total 61.3% of the oocytes presented a dysmorphy, involving, almost equally, the different oocyte compartments. Among the dysmorphic oocytes, half presented more than one anomaly. On average, 9.2% of the oocytes were lysed the day after the micro-injection. The oocytes presenting an enlarged perivitelline space, or multiple vacuoles had a significantly raised lyse rate, 16.3% and 27.8%, respectively. The day after micro-injection, 61.3% of the intact oocytes were fertilized. The rate of fertilization was correlated to the number of abnormalities per oocyte: 1 anomaly: 64.6%, > or = 3 anomalies: 54.6%. The oocytes presenting a large perivitelline space had a slightly lowered fertilization rate (53.4%). On the other hand, those showing a cytoplasm containing refractile bodies had a slightly raised fertilization rate (68.6%). We did not see any statistically significant difference between the different types of oocytes concerning embryonic development at d2., Conclusion: These results confirm and contribute new elements with respect to previously published data, showing that (i) oocyte morphology little affects fertilization and the first stages of embryonic development; (ii) certain dysmorphies, (enlargement of the perivitelline space) are specifically deleterious at certain stages in the process (lowering the fertilization rate); (iii) certain morphological differences (the presence of refringent bodies) are not anomalies, but can reflect physiological cellular changes.

Purpose: Trabecular meshwork, which is involved in aqueous outflow resistance, is deeply modified in glaucoma patients, with a decrease in the trabecular cell number. Trabecular toxicity of antiglaucoma medications cannot be excluded. On a human cultured trabecular cell line, we investigated the potential proapoptotic effect of a beta-blocker with or without preservative, benzalkonium chloride (0.01% BAC), by flow cytometry and confocal microscopy., Material: and, Methods: A human immortalized trabecular cell line (HTM-5) obtained from a normal donor was cultured under normal conditions. Preserved 0.25% betaxolol suspension (betaxolol BAC +), unpreserved 0.25% betaxolol suspension, and 0.01% BAC were respectively added to the culture medium in a 1/10 or 1/100 dilution for 15 minutes. After a 24-hour recovery period in normal culture conditions, cell size and the expression of an apoptotic marker, Apo 2.7, were evaluated by flow cytometry and confocal microscopy. Untreated trabecular cells were used as control cells., Results: Preserved and unpreserved betaxolol in a 1/10 dilution induced a significant decrease in trabecular cell size compared to controls. However, this cell size decrease was less pronounced than that induced by BAC at the same dilution. Similar results were obtained with betaxolol and BAC in a 1/100 dilution. Trabecular cell Apo 2.7 expression was significantly increased after treatment with betaxolol BAC + and BAC- in a 1/10 dilution compared to controls (36.8%, 28.1%, and 15.4%, respectively p<0.005). However, this proapoptotic activity was much less pronounced than that induced by BAC- at the same dilution (96.9%, p<10(-4)). Unpreserved betaxolol in a 1/100 dilution had no apoptotic activity on trabecular cells. Trabecular cell Apo 2.7 expression slightly increased with betaxolol BAC + at a 1/100 dilution (24.9%, p=0.04), while it was greatly increased with BAC at the same dilution (39.9%; p<10(-4))., Conclusion: In our model, unpreserved betaxolol at a low concentration displayed no proapoptotic activity on trabecular cells. On the other hand, preserved betaxolol displayed a moderate proapoptotic activity by triggering cell death of around 25% of cells. Trabecular cell toxicity appeared to be mainly due to the preservative benzalkonium chloride (BAC). Taken together, our results demonstrated that the strong apoptotic activity of BAC was greatly reduced within the preserved eye drops, probably through the interaction of BAC with the active compound.

Mouse resident peritoneal macrophages loaded with Fluo-3 were examined for changes in cytosolic calcium concentration ([Ca2+]i) after stimulation with gamma-hexachlorocyclohexane (Lindane or gamma-HCCH). These studies, realized on macrophage populations, or single cells, by digital imaging microscopy, sought to determine the role of calcium influx on cyclical changes according to maturation stages of macrophages. Single cell analysis of [Ca2+]i changes in macrophages, after gamma-HCCH exposure in 600 microM extracellular calcium, demonstrated that: 1) these [Ca2+]i variations were asynchronous oscillations with the same frequency (1.7 min-1), and 2) these [Ca2+]i variations in macrophages were not at the same [Ca2+]i level. This heterogeneity could be correlated to a cell size partition of the macrophage population (10.1 +/- 0.44 and 11.45 +/- 0.43 microns). In the presence of 100 microM calcium, gamma-HCCH induced a calcium influx into the two subpopulations, but the calcium oscillations appeared only in small macrophages. In the largest ones, [Ca2+]i slowly decreased back down to the basal level. The cell size variation could be correlated to a phenotypic heterogeneity, linked to the differenciation stage of the cell. Peroxydase activity showed that small macrophages were in fact exudate macrophages and the largest ones were resident macrophages. Inhibition of the oscillatory patterns by a decrease in the extracellular calcium concentration ([Ca2+]ext) or by lanthanum chloride (LaCl3) addition is indicative of the important role of calcium influx in the triggering of oscillations. The calcium influx was transient and induced inositol phosphate (InsP3) production in macrophages. The maintainance of these calcium oscillations depended on calcium mobilization from intracellular calcium stores by InsP3, since neomycin and 8-(diethylamino) octyl 3,4,5-trimethoxybenzoate (TMB-8) abolished the oscillations. gamma-HCCH induced a transient calcium entry which triggered phospholipase C activation and the associated [Ca2+]i oscillations. However, we showed that differences in cell responses were observed in relationship with the differentiation stage of the mouse peritoneal macrophages, and with the extracellular calcium concentration.

Dorsal closure (DC) is a morphogenetic movement that establishes the dorsal ectoderm of the drosophila embryo. During this process, the two lateral epithelia stretch toward the dorsal midline, the suture line of the two leading edges. Cell migration during DC relies both on cell shape change controlled by the activity of the JNK pathway in the leading edge cells and modification of cell adhesiveness, probably dependent upon activation of the Dpp (TGF-beta) pathway. Coupling of the JNK and TGF-beta pathways is essential. The sequence of the cellular and molecular events of DC highlights interesting common features with wound healing in vertebrates. Like DC, wound healing relies on the migration of epithelia bordered by leading edges controlling the direction and speed of the movement. This review summarizes recent data concerning the control of epithelial morphogenesis during DC and the bases of wound healing. The molecular and cellular events that underlie these two analogous migratory processes are detailed, discussed and compared. We suggest that DC is a good genetic model for wound healing studying.

Purpose: The effects of human recombinant bFGF has been evaluated on 9 paired human donor corneas (age 75 +/- 8 years), preserved in organ culture medium., Material and Methods: The endothelium of corneas were mechanically wounded (area of 7.53 +/- 2.05 mm2) and placed in culture medium during 14 days. For each pair, one cornea was tested with bFGF (50 ng/ml), delivered in two times (day 0, day 7), according to the stockage of the bFGF on the basal membranes (low affinity receptor), while the ipsilateral cornea served as control. Endothelium was assessed by trypan staining at day 0, day 7, and day 14. At this term of fourteenth day, alizarine red and trypan blue staining permitted morphometric data., Results: The bFGF factor increases significantly cell density in the wound area (p < 0.05), and in the transitional area (p < 0.01), compared to the control group. In the transitional area, cells depletion was only 15% (392 +/- 55 cells/mm2) in the treated group compared to the 28% (716 +/- 0.1 cells/mm2) in the untreated group. In the wound area, the mean cell area was averaged 2581 microns2 in the control group and 2161 microns2 in the bFGF treated group (p < 0.05); in the transitional area the mean cell size was 549 microns2, and 479 microns2 in the control and the bFGF treated group (p < 0.05) respectively. The bFGF group do not affect the shape factor., Conclusion: This assay demonstrates that human bFGF greatly facilitates wound closure in endothelium of human cornea. The cellular migration from the transitional zone seems the dominant healing mechanism.

Certain amino acids such as glutamine and proline stimulate liver glycogen synthesis and lipogenesis. This implies cell swelling and leads to the activation of glycogen synthase and acetyl-CoA carboxylase by a common mechanism. This mechanism results from the cell response to swelling and involves a fall in intracellular concentration of chloride ions and an increase in intracellular concentration of glutamate and aspartate. These ions indeed regulate the protein phosphatases that activate glycogen synthase and acetyl-CoA carboxylase.

Among the non-Hodgkin's malignant lymphomas of the dog, which are largely dominated by the centroblastic heterogeneous type, there is an original form of malignant lymphoma which is homogeneous and diffuse, with macronucleolated medium-sized cells. These cells seem to be morphologically very similar to those which constitute the majority population in the marginal zone of the secondary follicle of the lymph node in the dog, and which appear in the course of certain conditions: systemic lupus erythematosus, leishmaniasis, satellite lymph nodes in benign or malignant tumors. The aim of this study was twofold: on the one hand to establish, in the canine species, the identity of the lymphomatous cells and the reactive cells that make up the marginal zone, i.e. the filiation between the hyperplastic marginal zones and the macronucleolated malignant lymphoma with medium-sized cells, and, on the other hand, to compare this type of malignant lymphoma with those which are reputed to originate in the marginal zone in humans, for example the malignant lymphoma of the lymphoid tissue associated with the mucous membranes, and the monocytoid malignant B-cell lymphomas. Ninety four malignant lymphomas were observed between 1989 and 1994 at the Veterinary School in Lyon; these consisted of 71 cases showing medium or high-grade malignancy, 17 cases with small cells, of low-grade malignancy, and 6 cases of mycosis fungoides. Among the 71 cases of medium and high-grade malignancy, 8 were immunoblastic, 5 centroblastic homogeneous, 50 centroblastic heterogeneous, and 8 homogeneous with macronucleolated medium-sized cells. The methods used in these 94 cases were of a morphological type: cytology, histology, transmission microscopy and immunohistochemistry. The cytohistological, ultrastructural and immuno-phenotypical characteristics (CD3-, CIg-, Ki-67- phenotype) of the lymphomatous cells and the cells of the marginal zone were found to be identical, in the dog; this strongly suggests B-lineage cells which do not secrete cytoplasmic immunoglobulins and are not involved in the cell cycle. Finally, these cells seem to us to be morphologically very similar to the minority population described by Van den Oord in the marginal zone of the secondary follicles in the lymph node in humans, in certain reactive situations.

The effect of Trypanosoma congolense on testis was studied in 53 trypano-resistant "Baoulé" bulls by quantitative histology and morphometry. The daily spermatozoa production per testis of control groups (n = 45) was 382 +/- 334 x 10(6) (m +/- sd) and the epididymis contained 0.6 +/- 1 x 10(9) spermatozoa in the caput, 0.3 +/- 0.3 x 10(9) in the corpus and 1.2 +/- 1.8 x 10(9) in the cauda. The infected bulls (n = 8) showed no significant difference (P > 0.05) when compared to the control despite their average low value. The morphometric analysis during infection revealed a significant (P < 0.05) decrease (32%) of total Leydig cell volume per testis, 4.4 +/- 0.9 cm3 for the control (n = 5) and 3.0 +/- 0.8 cm3 for infected bulls (n = 8). The number of round spermatids per Sertoli cell and the daily round spermatid production (DRSP) per testis were also significantly reduced in infected bulls when compared to controls (P < 0.05), 5.2 +/- 0.7 and 2.8 +/- 2 for round spermatid per Sertoli cell and 6.1 +/- 2.0 and 3.1 +/- 1.9 x 10(8) for DRSP. These observations indicate that Trypanosoma congolense infection alters the interstitial tissue and meotic divisions of germinal cells leading to low daily round spermatid production per gram of testis in "Baoulé" bulls.

The number and the average diameter of the myelinated fibers have been recorded in the both medial gastrocnemius nerves in the rat. The study concerned foetus at the end of the intra-uterine life as well as old rats (24 months). It seemed the absolute necessity to collect these data before studying the consequences of age on nervous regeneration. Electron microscopy was used in very small samples, photonic microscopy in bigger ones. The first myelinated fibers appear during the first day of life. Their number becomes steady around 2 months of live. But their diameter changes and increases until the end of the 6th month. In pubescent animals, the global variations between the two sides are negligible (average right number 260 +/- 8 fibers, average left 258 +/- 12, average right diameter 1.7 +/- 0.7 microns, average left diameter 7.1 +/- 0.6 microns).